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In light of the worthy design flexibility and the good signal amplification capacity, the recently developed DNA motor (especially the DNA walker)-based fluorescent biosensors can offer an admirable choice for realizing bioimaging. However, this attractive biosensing strategy not only has the disadvantage of uncontrollable initiation but also usually demands the supplement of exogenous driving forces. To handle the above obstacles, some rewarding solutions are proposed here. First, on the surface of an 808 nm near-infrared light-excited low-heat upconversion nanoparticle, a special ultraviolet upconversion luminescence-initiated three-dimensional (3D) walking behavior is performed by embedding a photocleavage linker into the sensing elements, and such light-controlled target recognition can perfectly overcome the pre-triggering of the biosensor during the biological delivery to significantly boost the sensing precision. After that, a peculiar self-driven walking pattern is constructed by employing MnO2 nanosheets as an additional nanovector to physically absorb the sensing frame, for which the reduction of the widespread glutathione in the biological medium can bring about sufficient self-supplied Mn2+ to guarantee the walking efficiency. By selecting an underlying next-generation broad-spectrum cancer biomarker (survivin messenger RNA) as the model target, we obtain that the newly formed autonomous 3D DNA motor shows a commendable sensitivity (where the limit of detection is down to 0.51 pM) and even an outstanding specificity for distinguishing single-base mismatching. Beyond this sound assay performance, our sensing approach is capable of working as a powerful imaging platform for accurately operating in various living specimens such as cells and bodies, showing a favorable diagnostic ability for cancer care.
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Técnicas Biossensoriais , Nanopartículas , DNA/genética , Glutationa , Luminescência , Compostos de Manganês , ÓxidosRESUMO
The further development of high-performance fluorescent biosensors to image intracellular microRNAs is beneficial to cancer medicine. By virtue of the need for enzymes and hairpin DNA probes, the entropy-driven reaction-assisted signal amplification strategy has shown an enormous potential to accomplish this task. Nevertheless, this good option still meets with poor biostability, low cell uptake efficiency, and unsatisfactory accuracy. On the basis of these challenges, we put forward here a battery of solving pathways. First, the straight DNA probes are anchored onto the vertexes of dual DNA tetrahedrons, and thus the enzyme resistance of the whole sensing system is observably enhanced. A metal-organic framework (ZIF-8 nanoparticle), which can be effectively dissociated into a weakly acidic environment, then is employed as an additional delivery vehicle to encapsulate such a DNA tetrahedron sustained biosensor and finally bring about a more efficient endocytosis. Last, a kind of photocleavage-linker triggered photoresponsive manner is incorporated to achieve an exceptional precise target identification, by which the biosensor can only be initiated under the irradiation of an externally mild 365 nm ultraviolet light source. In accordance with the above efforts, worthy assay performance toward microRNA-196a has given rise to this newly constructed biosensor, whose sensitivity is down to 2.7 pM and also able to distinguish single-base variation. Beyond that, the amplifier can work as a powerful imaging toolbox to accurately determine the targets in living cells, providing a promising intracellular sensing platform.
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Técnicas Biossensoriais , Estruturas Metalorgânicas , MicroRNAs , DNA , Entropia , MicroRNAs/genéticaRESUMO
Despite that the currently discovered CRISPR-Cas12a system is beneficial for improving the detection accuracy and design flexibility of luminescent biosensors, there are still challenges to extend target species and strengthen adaptability in complicated biological media. To conquer these obstacles, we present here some useful strategies. For the former, the limitation to nucleic acids assay is broken through by introducing a simple functional DNA regulation pathway to activate the unique trans-cleavage effect of this CRISPR system, under which the expected biosensors are capable of effectively transducing a protein (employing dual aptamers) and a metal ion (employing DNAzyme). For the latter, a time-gated luminescence resonance energy transfer imaging manner using a long-persistent nanophosphor as the energy donor is performed to completely eliminate the background interference and a nature-inspired biomimetic periodic chip constructed by photonic crystals is further combined to enhance the persistent luminescence. In line with the above efforts, the improved CRISPR-Cas12a luminescent biosensor not only exhibits a sound analysis performance toward the model targets (carcinoembryonic antigen and Na+) but also owns a strong anti-interference feature to actualize accurate sensing in human plasma samples, offering a new and applicative analytical tool for laboratory medicine.
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Técnicas Biossensoriais , DNA Catalítico , Biomimética , Sistemas CRISPR-Cas/genética , DNA/genética , Humanos , LuminescênciaRESUMO
OBJECTIVE To analyze the situation of drug use in medical institutions of Guangdong area from 2017 to 2022, and to provide reference for the production, sale and procurement of drugs by government departments, medical insurance departments, pharmaceutical enterprises, drug sales enterprises and hospitals. METHODS Using the retrospective analysis method, based on original data from Guangdong hospital information network from 2017 to 2022, statistical analysis was conducted on the drug procurement amount of 118 medical institutions that had been online for the past 6 years, as well as the distribution of 14 major categories of drugs among all purchased drugs by online medical institutions, and sales amount of drug production enterprises. RESULTS The drug procurement amount of 118 medical institutions that had been online in Guangdong area from 2017 to 2022 showed a growth-negative growth-slow growth trend. Among the 14 major categories of drugs, the top 5 drugs in the list of consumption sum were anti-infective drugs, cardiovascular drugs, nervous system drugs, anti-tumor drugs, and digestive system drugs; among the top 200 drugs in terms of procurement amount, three major categories of drugs, namely the anti-infective drugs, anti-tumor drugs and cardiovascular system drugs, occupied the main position. The top 10 drugs in the list of procurement amounts were mainly anti-tumor drugs and cardiovascular system drugs; foreign manufacturers occupied the top 3 places in the list of sales amounts in medical institutions of Guangdong area. CONCLUSIONS In Guangdong area, the growth of drug procurement amount in medical institutions is gradually slowing down, the usage of anti-infective drugs is still abundant, the prevention and treatment of chronic diseases need great attention, and foreign pharmaceutical companies are in a leading position in the sales amount of medical institutions.
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Activation-induced cytidine deaminase (AID) is required for the generation of antibody diversity through initiating both somatic hypermutation (SHM) and class switch recombination. A few research groups have successfully used the feature of AID for generating mutant libraries in directed evolution of target proteins in B cells in vitro. B cells, cultured in suspension, are not convenient for transfection and cloning. In this study, we established an AID-based mutant accumulation and sorting system in adherent human cells. Mouse AID gene was first transfected into the human non-small cell lung carcinoma H1299 cells, and a stable cell clone (H1299-AID) was selected. Afterwards, anti-hTNF-α scFv (ATscFv) was transfected into H1299-AID cells and ATscFv was displayed on the surface of H1299-AID cells. By 4-round amplification/flow cytometric sorting for cells with the highest affinities to hTNF-alpha, two ATscFv mutant gene clones were isolated. Compared with the wild type ATscFv, the two mutants were much more efficient in neutralizing cytotoxicity of hTNF-alpha. The results indicate that directed evolution by somatic hypermutation can be carried out in adherent non-B cells, which makes directed evolution in mammalian cells easier and more efficient.
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Animais , Humanos , Camundongos , Afinidade de Anticorpos , Células Cultivadas , Citidina Desaminase , Genética , Metabolismo , Células HEK293 , Região Variável de Imunoglobulina , Genética , Alergia e Imunologia , Mutação , Anticorpos de Cadeia Única , Química , Genética , Alergia e Imunologia , Hipermutação Somática de Imunoglobulina , Genética , Alergia e Imunologia , Fator de Necrose Tumoral alfa , Alergia e ImunologiaRESUMO
The Rad1 gene is evolutionarily conserved from yeast to human. The fission yeast Schizosaccharomyces pombe Rad1 ortholog promotes cell survival against DNA damage and is required for G(2)/M checkpoint activation. In this study, mouse embryonic stem (ES) cells with a targeted deletion of Mrad1, the mouse ortholog of this gene, were created to evaluate its function in mammalian cells. Mrad1 (-/-) ES cells were highly sensitive to ultraviolet-light (UV light), hydroxyurea (HU) and gamma rays, and were defective in G(2)/M as well as S/M checkpoints. These data indicate that Mrad1 is required for repairing DNA lesions induced by UV-light, HU and gamma rays, and for mediating G(2)/M and S/M checkpoint controls. We further demonstrated that Mrad1 plays an important role in homologous recombination repair (HRR) in ES cells, but a minor HRR role in differentiated mouse cells.
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Animais , Camundongos , Divisão Celular , Proliferação de Células , Dano ao DNA , Reparo do DNA , Células-Tronco Embrionárias , Metabolismo , Exonucleases , Genética , Metabolismo , Fisiologia , Fase G2 , Raios gama , Deleção de Genes , Hidroxiureia , Farmacologia , Raios UltravioletaRESUMO
Objective To study the clinical application of Yashiro catheter in chemoembolization of pelvic tumors.Methods Yashiro catheters were used in 11 of 23 cases with pelvic tumors who using Cobra catheter could not insert into homolateral internal iliac artery and median sacral artery,the blood supply arteries of tumors were found and selective chemoembolism was performed.The embolism of main stemof bilateral internal iliac arteries were done except the blood supply arteries of tumors with gelfoam in 12 of 23 cases and resection wasperformed by the same surgeons in 24~48 hours after chemoembolization.Results The time of intubatton in one branch of homolateralinternal iliac artery and median sacral artery was obviously shorten with Yashiro catheters.Superselective intubatton was successful in allpatients.The tumors were easy to strip,less bleeding and short operation time during operation.There were not recurrence followed-up 6~18 months after operation.Conclusion Chemoembolization of pelvic neoplasm by Yashiro is an effective and safe technique,it is beneficial to the removal of the pelvic tumor completely and reducing the recurrence of the tumors or metastasis.
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Objective To discuss the curative effect of hysteromyoma by uterine artery embolism.Methods The Seldinger's method was used for uterine artery embolism to treat hysteromyoma in 47 cases.The size of tumor and clinical symptoms were observed 3 and 6 months later after treatment.Results The blood supply of hysteromyoma was from uterine artery branches and mostly were bilateral blood supply style.6 months later after treatment ,the tumors were shrinked and clinical symptoms improved markedly in all cases.Conclusion The recent effect of intervenlional treatment for hysteromyoma is good.Infiltration anesthesia of uterine cavity can distinctly reduce incidence of pelvic cavity pain.
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Objective To explore the curative effects of uterine arterial embolization(UAE) in treating adenomyosis.Methods Bilateral UAE was performed by Seldinger’s technique in 39 patients with adenomysis (11 cases coexisted with uterine leiomyoma).The catamenia,menorrhalgia,anemia,the size of uterus and lesions were observed after procedure.Results 6 months after treatment,mean catamenia was reduces 56.2%(?